<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <title>Placing Objects in an Entity Store</title>
    <link rel="stylesheet" href="gettingStarted.css" type="text/css" />
    <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
    <link rel="start" href="index.html" title="Getting Started with Berkeley DB" />
    <link rel="up" href="persist_access.html" title="Chapter 5. Saving and Retrieving Objects" />
    <link rel="prev" href="simpleda.html" title="SimpleDA.class" />
    <link rel="next" href="simpleget.html" title="Retrieving Objects from an Entity Store" />
  </head>
  <body>
    <div xmlns="" class="navheader">
      <div class="libver">
        <p>Library Version 12.1.6.2</p>
      </div>
      <table width="100%" summary="Navigation header">
        <tr>
          <th colspan="3" align="center">Placing Objects in an Entity Store</th>
        </tr>
        <tr>
          <td width="20%" align="left"><a accesskey="p" href="simpleda.html">Prev</a> </td>
          <th width="60%" align="center">Chapter 5. Saving and Retrieving Objects</th>
          <td width="20%" align="right"> <a accesskey="n" href="simpleget.html">Next</a></td>
        </tr>
      </table>
      <hr />
    </div>
    <div class="sect1" lang="en" xml:lang="en">
      <div class="titlepage">
        <div>
          <div>
            <h2 class="title" style="clear: both"><a id="simpleput"></a>Placing Objects in an Entity Store</h2>
          </div>
        </div>
      </div>
      <p>
                    In order to place an object in a DPL entity store,
                    you must:
            </p>
      <div class="orderedlist">
        <ol type="1">
          <li>
            <p>
                                    Open the environment and store.
                            </p>
          </li>
          <li>
            <p>
                                    Instantiate the object.
                            </p>
          </li>
          <li>
            <p>
                                    Put the object to the store using the
                                    <code class="methodname">put()</code> method
                                    for the object's primary index.
                            </p>
          </li>
        </ol>
      </div>
      <p>
                    The following example uses the <code class="classname">SimpleDA</code>
                    class that we show in <a class="xref" href="simpleda.html" title="SimpleDA.class">SimpleDA.class</a> to put a
                    <code class="classname">SimpleEntityClass</code> object (see
                    <a class="xref" href="persist_access.html#simpleentity" title="A Simple Entity Class">A Simple Entity Class</a>) to the
                    entity store.
            </p>
      <p>
                To begin, we import the Java classes that our example
                needs. We also instantiate the private data members that we
                require.
           </p>
      <pre class="programlisting">package persist.gettingStarted;

import java.io.File;
import java.io.FileNotFoundException;

import com.sleepycat.db.DatabaseException;
import com.sleepycat.db.Environment;
import com.sleepycat.db.EnvironmentConfig;

import com.sleepycat.persist.EntityStore;
import com.sleepycat.persist.StoreConfig; 

public class SimpleStorePut {

    private static File envHome = new File("./JEDB");

    private Environment envmnt;
    private EntityStore store;
    private SimpleDA sda; </pre>
      <p>
            Next we create a method that simply opens our database
            environment and entity store for us. 
    </p>
      <pre class="programlisting">   // The setup() method opens the environment and store
    // for us.
    public void setup()
        throws DatabaseException {

        EnvironmentConfig envConfig = new EnvironmentConfig();
        StoreConfig storeConfig = new StoreConfig();

        envConfig.setAllowCreate(true);
        storeConfig.setAllowCreate(true);

        try {
            // Open the environment and entity store
            envmnt = new Environment(envHome, envConfig);
            store = new EntityStore(envmnt, "EntityStore", storeConfig);
        } catch (FileNotFoundException fnfe) {
            System.err.println("setup(): " + fnfe.toString());
            System.exit(-1);
        }
    } </pre>
      <p>
            We also need a method to close our environment and store.
    </p>
      <pre class="programlisting">    // Close our environment and store.
    public void shutdown()
        throws DatabaseException {

        store.close();
        envmnt.close();
    } </pre>
      <p>
            Now we need to create a method to actually write objects to our
            store. This method creates a <code class="classname">SimpleDA</code>
            object (see <a class="xref" href="simpleda.html" title="SimpleDA.class">SimpleDA.class</a> that we
            will use to access our indexes. Then we instantiate a series
            of <code class="classname">SimpleEntityClass</code> (see <a class="xref" href="persist_access.html#simpleentity" title="A Simple Entity Class">A Simple Entity Class</a>) 
            objects that we
            will place in our store. Finally, we use our primary index
            (obtained from the <code class="classname">SimpleDA</code> class
            instance) to actually place these objects in our store.
    </p>
      <p>
            In <a class="xref" href="simpleget.html" title="Retrieving Objects from an Entity Store">Retrieving Objects from an Entity Store</a>
            we show a class that is used to retrieve these objects.
    </p>
      <pre class="programlisting">    // Populate the entity store
    private void run()
        throws DatabaseException {

        setup();

        // Open the data accessor. This is used to store
        // persistent objects.
        sda = new SimpleDA(store);

        // Instantiate and store some entity classes
        SimpleEntityClass sec1 = new SimpleEntityClass();
        SimpleEntityClass sec2 = new SimpleEntityClass();
        SimpleEntityClass sec3 = new SimpleEntityClass();
        SimpleEntityClass sec4 = new SimpleEntityClass();
        SimpleEntityClass sec5 = new SimpleEntityClass();

        sec1.setPKey("keyone");
        sec1.setSKey("skeyone");

        sec2.setPKey("keytwo");
        sec2.setSKey("skeyone");

        sec3.setPKey("keythree");
        sec3.setSKey("skeytwo");

        sec4.setPKey("keyfour");
        sec4.setSKey("skeythree");

        sec5.setPKey("keyfive");
        sec5.setSKey("skeyfour");

        sda.pIdx.put(sec1);
        sda.pIdx.put(sec2);
        sda.pIdx.put(sec3);
        sda.pIdx.put(sec4);
        sda.pIdx.put(sec5);

        shutdown();
    } </pre>
      <p>
            Finally, to complete our class, we need a
            <code class="methodname">main()</code> method, which simply calls our
            <code class="methodname">run()</code> method.
    </p>
      <pre class="programlisting">    // main
    public static void main(String args[]) {
        SimpleStorePut ssp = new SimpleStorePut();
        try {
            ssp.run();
        } catch (DatabaseException dbe) {
            System.err.println("SimpleStorePut: " + dbe.toString());
            dbe.printStackTrace();
        } catch (Exception e) {
            System.out.println("Exception: " + e.toString());
            e.printStackTrace();
        }
        System.out.println("All done.");
    }

} </pre>
    </div>
    <div class="navfooter">
      <hr />
      <table width="100%" summary="Navigation footer">
        <tr>
          <td width="40%" align="left"><a accesskey="p" href="simpleda.html">Prev</a> </td>
          <td width="20%" align="center">
            <a accesskey="u" href="persist_access.html">Up</a>
          </td>
          <td width="40%" align="right"> <a accesskey="n" href="simpleget.html">Next</a></td>
        </tr>
        <tr>
          <td width="40%" align="left" valign="top">SimpleDA.class </td>
          <td width="20%" align="center">
            <a accesskey="h" href="index.html">Home</a>
          </td>
          <td width="40%" align="right" valign="top"> Retrieving Objects from an Entity Store</td>
        </tr>
      </table>
    </div>
  </body>
</html>
